Fuel system



April 28, 1931. c. E. SUMMERS FUEL SYSTEM Filed June 5 192 3Sheets-Sheet 1 gmwnio'a Ap 1931. c. E. SUMMERS 1,802,848

FUEL SYSTEM Filed June 5 92 3 Sheets-Sheet 2 37141. vJo,

Guam

April 28, 1931.

C. E. SUMMERS FUEL SYSTEM Filed June 5 1925 5 Sheets-Sheet 3 PatentedApr. 28, 1931 UNITED STATES PATENT OFFICE CALEB E. SUMMERS, OF DETROIT,MICHIGAN, ASSIGNOR TO GENERAL MOTORS RE- SEARCH CORPORATION, OF DETROIT,MICHIGAN, A CORPORATION OF DELAWARE FUEL SYSTEM Application filed June5,

This invention relates to improvements in the fuel system for explosivemotors. The invention is primarily intended for use on motor vehiclesalthough itsadvantages, when so used, may also be present, perhaps to aless extent, in other relations. Furthermore, while designed for use onan engine of the four cycle type its characteristics are such as torender it useful also on engines of the two cycle type.

It is, then, the object of the invention to provide a fuel system havingparts co-related to obtain maximum etlieiency; one which will useadvantageously explosive fuel ditlicult of vaporization; bne which isadapted for all conditions of speed, load, temperature and pressure.

The duty of a fuel system is to bring fuel from a storage tank at therear; meter it correctly for every condition of speed, load, andtemperature; and introduce it in an atomized state so it is carrieddirectly, borne by the air charge, into each separate cylinder. The fuelshould be automatically regulated for every requirement, as, extra richfor cold starting, full power mixture for full load, and maximum economymixture for part'load. The fuel system should also be so designed as toget the maximum air charge into the motor at full load. To accomplishthis, preheating must be eliminated, and also any resistance to theentrance of the air, such as valves, is undesirable. It is desirableeven to go further, and so construct the manifold that an air ramcondition is produced, which actually supercharges the engine, obtainingmore power from a given bore and stroke, yet without increasing thespeed or compression (which latter two carry with them certaindisadvantages). This results in 'a lighter motor for equal power, whichnot only saves cost of material, but saves weight, which again resultsin better performance for the same power. Also a smaller engine withless cooling surface, of less mechanical friction, results in greatereconomy. It is, therefore, a fundamental gain to obtain as great aweight of charge as possible in a given cylinder.

For the attainment of the objects enumer- 1926. Serial No. 113,933.

ated, the structure herein described and illustrated in the accompanyingdrawing has been devised.

In the drawing Figure 1 shows an internal combustion engine in endelevation, partly in section.

Figure 2 is a side elevation with the fuel system in vertical section.

Figure 3 is a horizontal section on line 33 of Figure 2.

Figure 4 is a horizontal section on 4-.4 of Figure 2.

Figure 5 is a vertical section of a detail.

Referring by reference characters to the drawing, numeral 1 shows aninternal combustion engine having exhaust manifold 2. The cylinders 3are surrounded by a Water jacket 4. Over the cylinder block is a 00-operating head 5 which may be shaped as shown, and in which head aremounted the spark plugs 6. Associated with each cylinder is an intakevalve 7 affording communication with the combustion chamber 8 and themanifold 9. At this point there is a departure from the conventionalarrangement. There are a plurality of tubular manifold members which aresecured to openings 9 in the cylinder block and extend downwardly andare united by a common casting 10 controlled by the usual throttle valve11. By this type of manifold construction each cylinder draws in its airthrough a tube which is not being used at the time by any othercylinder, that is, there is no overlapping of induction flow to twocylinders through the same tube. By proper selection of length anddiameter of the tube, the ram efl'ect will be varied along the speedrange so as to obtain the maximum ram at the speed desired. Forinstance, if high torque at high speed is the principal requirement, theram will be relatively short and large in diameter; if high torque atloW speed is more important, the ram will be relatively long and ofsmall diameter. In practice, for application to an Oakland engine, theram tubes will be approximately inside diameter and 19" long. In theconstruction of a ram, it is desirable to have the inner surface smoothand all bends over as long radius as possible.

line

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Where there isv a change in section, as where the ram enters the ort,the increase in diameter should be gra ual so there is no distant ledgewhich will cause eddy currents of the air and dissipate energy in fluidfriction.

Air pumps 12, of which there may be two, are driven from the motor as bya shaft 13, gearing 13', shaft 14, universal 15, crank shaft 16,connecting rods 17 and piston 18. The air pumps draw air by means of aninlet valve 19 through which air enters from a tube 21. Tube 21 takesits air from any convenient source but preferably from the crank casesince in that way the air would be free from dirt and contain a desiredquantity of oil mist. A resistance valve, not shown, is used in pipe 21-to maintain a definite vacuum. This vacuum is communicated by pipe 23 tofloat chamber 24 having a float 25 controlling a valve 26. Obviously thedegree of vacuum must be sufiicient to lift the fuel from the storagetank to the float chamber under the most adverse conditions and maxiumdemand, that is, it must lift sufficient fuel for maximum engine speedat full load when climbing the steepest grade so the car will pull onlow gear and with the storage tank practically empty.

The air inlet valve 19 is mechanically operated and driven by shaft 27geared by gears 28 and 56 to the crank shaft. The fuel for the floatchamber is obtained by a pipe 29 extending from the usual gas reservoirat the rear of the car and. enters a chamber 30 beneath the floatchamber. Here it is filtered by filter 32 and passes through the valve26 into the float chamber.

To meter the fuel one or more rotating cylinders 33 are used. The twocylinders shown are mounted so as to be capable of simultaneous verticalreciprocation and each is mounted for rotation on its own longitudinalaxis. Each cylinder rotates in a chamber filled with fuel entering fromthe float chamber through passage 34 (see Figure 3). Shoes 35 actuatedby a spring 36 mounted on a post 37 hold about 90 of the circumferenceof the cylinders 33 against the encircling walls of the fuel chamber.The cylinder walls are provided with pockets 38 of variable depths,being deepest at their lowermost portion. These pockets become filledwith fuel during the rotation of the cylinder within the fuel chamber.The pockets 38 come into registration with the openings 39 in the fuelchamber as the cylinder rotates on its axis and the openings 39communicate bymeans of pipes 40 with each of the valve chambers, asclearly shown in Figure 1. The pipes 40 terminate in nozzles 41 situatedjust beneath the intake valves. The fuel pockets 38, when rotated intoregistry with opening 39 also register with elongated openings 44 in thewalls of the fuel chamber, said elongated openings 44' communicatingwith a motor is at its lowest temperature. For operation under normalconditions of temperature and for part load, the metering cylinder ismoved downward so the fuel in the lower portion of the fuel pocket doesnotdischarge through the port, but is carried past it. The means formoving the metering cylinder as itctuated by temperature and load are asfolows:

The shaft45, which drives the metering cylinders, extends downwardly asat 46.

This shaft and its companion shaft 47, which drives the other meteringcylinder, are driven by gears 53 on the shafts. Gears'53 engage gear 55,which is integral with the gear 57,

rotated by the gear 56 on the crank shaft as shown in Figure 1 andFigure 3. The shafts are coupled by a yoke 48 which permits them torotate independently but causes them to move together in any verticalmovement. The yoke 48 has a pivot shaft 49 upon which is a lever 50, oneend of which is connected to a piston 51 of a cylinder 52.

Cylinder 52 is connected by a conduit 58 entering the manifold at 59just above the throttle 11. A spring 60 within cylinder 52 exerts itspressure upwardly upon piston 51. It is evident that when the vacuum inthe manifold increases, due to the closing of the throttle, the piston51 will be drawn downwardly carrying lever 50, yoke 48 and the meteringcylinders. spring of suitable tension and by properly shaping thepockets 38. it is possible to make the quantity of fuel discharged bythe metering cylinders correspond to any degree of throttling, since thefuel content is reduced in proportion to the absolute pressure of air inthe manifold, it being understood that the fuel in the fuel pocket 38beneath the discharge opening 39 is not driven out through the conduit40.

Air expands with increase in temperature. Therefore, a cylinder full ofair at minus 20 F. willrequire more fuel than the same volume at 200 F.Provision is made, therefore, to regulate the fuel in proportion totemperature. A bellows 61 is provided separated by partition 62 from aninclosure 63. The inelosure 63 is in communication by means of a tube 64with a chamber 65 located within the water jacket of the motor so thatthe water temperature is imparted to it. The bellows 61 is entirelyfilled with oil or other By the selection of a non-volatile liquid andit communicates by means of a small hole 61' through partition 62 withenclosure 63, the lower-most part of the enclosure also containing oil.

The size of the enclosure is so selected that when the bellows is fullyextended downward, liquid from the enclosure may flow through a smallhole in the partition entirely filling the bellows, with a certainreserve left in the enclosure. Also when the bellows is at its upwardlimit, thereby forcing the liquid out through the aperture in thepartition into the'enclosure, the enclosure will not be entirely filled.The purpose of the liquid is to give stability to the bellows so thatwhen sudden shocks are imparted to the bellows through the sudden andforceful change in the vacuum that controls the piston 51, the shockimparted to the bellows through the lever and the connection will notcause it to move suddenly, because a considerable time element will berequired for the oil to be forced through the aperture in the partition.However, on the other hand, when the temperature of the water jacketchanges and causes an expansion of the air in the cham-,

ber, the persistent pressure exerted on the surface of the liquid in theenclosure will cause the liquid to flow through the aperture, thusextending the bellows; and conversely when a contraction of the air inthe chamber produces a partial vacuum, the air pressure exerted on theexternal walls of the bellows will force the bellows upward, depressingthe portion of the liquid contained therein into the enclosure.Therefore, by this arrangement we have a mechanism which is resistant tosudden shocks, but regulates with accuracy to compensate for changes inthe temperature of the motor. The chamber may be placed at any positionto have the temperature of any portion desired imparted to it, but it isthought the water represents a fair index of the temperature of theworking fluid in the cylinder during the intake stroke. The bellows 61is secured to the cast ing 67 by its upper end so that its expansion hasthe effect of pulling down on leaf spring 68 imparting downward motionto the yoke 48 and the metering cylinders.

The bellows has been described as correcting for variations intemperature, but it is evident that it will also correct for changes inbarometer or altitude. Suppose a motor so equipped is placed in anairplane and is results in reducing the quantity of fuel which is beingfed to the motor so a balanced mixture is maintained.

We have, therefore, combined in one unit means for elevating the fuelfrom the storage a spray, produced by compressed air, so thedistributionshould be perfect and the introduction positive and almostinstantaneous. The ram manifold, which is possible with this type ofmetering, increases the air charge yery appreciably through the ordinarydriving range.

. From the combination of ram manifold, cold carburetion and perfectdistribution, the power of the engine may be increased by approximately20%. The method of fuel introduction is intended to insure easy startingat any temperature. It is expected that an engine equipped as describedwill start and operate satisfactory on half kerosene and half gasoline,even in winter. Fuel economy will be uniformly high whether the car isdriven by an expert or an amateur, since all regulation is automatic.

I claim 1. In combination with an internal combustion engine,amechanical metering device therefor comprising a fuel conduitcommunicating with said engine, a fuel chamber, a metering memberrotatable and reciprocable therein, said metering member having a pocketto receive fuel from said chamber and deliver it to said conduit, meansautomatically controlled to reciprocate said metering means and therebypredetermine the amount of fuel discharged from said pocket to saidconduit.

2. Mechanical metering mechanism for an internal combustion enginehaving a cylinder and an intake manifold comprising a fuel I chamber, aplurality of metering members therein, power driven means to rotate saidmembers, delivery conduits from said chamber to said cylinder forsupplying the engine with-fuel, said metering members having pockets tobe filled with fuel from said chamber and to discharge into saidconduits, pressure means to force said fuel through said conduits, andmechanism automatically actuated by variations in manifold suction,engine temperature and external pressure to reciprocate said meteringmembers jointly to thereby vary the area of said pockets in registeringwith said conduits.

3. The combination of elements enumerated in claim 2, said mechanismcomprising rod means on each metering member, a device responsive tochanges in manifold suction operative upon one arm of said lever and adevice responsive to changes in temperature and pressure operable uponthe other arm of i said lever device, the other arm being actuated bysaid temperature control.

4. The combination of elements enumerated in claim 2, said mechanismcomprising a head connected to said metering members, a fixed cylinder,a piston therein connected to said head, apipe connecting said cylinderwith the manifold and yielding means within said cylinder whereby thesuction of the manifold and the yielding means cooperate to reciprocatesaid metering device to vary the quantity of fuel delivery.

5. The combination of elements enumerated in claim 2, said mechanismcomprising a head connected to said metering members, an expansible'andcontractible member being connected to said head, whereby changes inmotor temperature control the quantity of fuel supplied by said meteringdevice.

6. In combination, an internal combustion engine, a float chamber forfuel, a mechanically motor operated air pump, pipe means between saidair pump and said fuel chamber whereby the fuel chamber is supplied withfuel by the suction stroke of the pump, other pipe means associated withsaid air pump and fuel chamber and engine whereby fuel is delivered fromsaid chamber to said engine by air pressure caused by the dischargestroke of said pump.

7. In an internal combustion engine having a cylinder and intakemanifold, a fuel chamher, a first conduit from said chamber to saidcylinder, a second conduit to supply said chamber with fuel from asource below said chamber, an engine operated air pump, an inlet pipetherefor, a pipe from said inlet pipe to said fuel chamber, mechanismincluding a third conduit between said pump and the first conduit,whereby the suction stroke of said pump operates to maintain a supply offuel in said chamber through the second conduit and whereby thedischarge stroke of said pump operates to deliver a supplyof fuel underair pressure from said chamber to said cylinder through said firstconduit.

8. The invention defined by claim 7 together with an engine operatedmetering de vice in said chamber to predetermine the quantity of fuel tobe delivered.

9-. The invention defined by claim 7, together with an engine-operatedmetering device in said chamber to predetermine the quantity of fuel tobe delivered, and mechanism responsive to changes in manifold suctionand also to variations in temperature and pressure to control themetering device.

In testimony whereof I aflix my si nature. CALEB E. SUM ERS.

